:root{--bg: #0f1117;--surface: #1a1d27;--surface-hover: #232734;--border: #2d3142;--text: #e4e6eb;--text-dim: #8b8f9a;--accent: #4c8eff;--accent-hover: #6ba1ff;--ok: #4ade80;--err: #f87171;--radius: 8px}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;min-height:100vh}.app{max-width:720px;margin:0 auto;padding:2rem 1.5rem}header{margin-bottom:2rem}header h1{font-size:1.75rem;font-weight:700}.subtitle{color:var(--text-dim);font-size:.875rem}main{display:flex;flex-direction:column;gap:1.5rem}.panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.5rem}.panel h2{font-size:1.125rem;margin-bottom:.25rem}.panel-desc{color:var(--text-dim);font-size:.8125rem;margin-bottom:1.25rem}.form-row{display:flex;flex-direction:column;gap:.375rem;margin-bottom:1rem}.form-row label{font-size:.8125rem;font-weight:500;color:var(--text-dim)}.form-row input[type=text]{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius);color:var(--text);font-size:.875rem;padding:.625rem .75rem;outline:none;transition:border-color .15s}.form-row input[type=text]:focus{border-color:var(--accent)}.form-row input[type=file]{font-size:.8125rem;color:var(--text-dim)}button{background:var(--accent);color:#fff;border:none;border-radius:var(--radius);font-size:.875rem;font-weight:500;padding:.625rem 1.25rem;cursor:pointer;transition:background .15s}button:hover:not(:disabled){background:var(--accent-hover)}button:disabled{opacity:.45;cursor:not-allowed}.checkbox-inline{display:inline-flex;align-items:center;gap:.375rem;margin-left:.75rem;font-size:.8125rem;color:var(--text-dim);cursor:pointer;-webkit-user-select:none;user-select:none}.checkbox-inline input[type=checkbox]{width:.9375rem;height:.9375rem;cursor:pointer;accent-color:var(--accent)}.status{margin-top:.75rem;font-size:.8125rem}.status-ok{color:var(--ok)}.status-err{color:var(--err)}.result{margin-top:.75rem;display:flex;flex-direction:column;gap:.5rem}.url-display{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius);padding:.625rem .75rem;font-size:.75rem;word-break:break-all;font-family:SF Mono,Monaco,Consolas,monospace;width:100%;color:var(--text);outline:none;transition:border-color .15s}.url-display:focus{border-color:var(--accent)}.download-link{color:var(--accent);font-size:.8125rem;text-decoration:none;align-self:flex-start}.download-link:hover{text-decoration:underline}